Adaptive algorithm of shaded-relief images from DEMs based on wavelet transform

Xiuguang Zhou; Egon Dorrer

doi:10.1117/12.227869

1 December 1995 Adaptive algorithm of shaded-relief images from DEMs based on wavelet transform

Xiuguang Zhou, Egon Dorrer

Proceedings Volume 2646, Digital Photogrammetry and Remote Sensing '95; (1995) https://doi.org/10.1117/12.227869
Event: Digital Photogrammetry and Remote Sensing '95, 1995, St. Petersburg, Russian Federation

Abstract

This paper presents an adaptive shading algorithm based on the wavelet transform. The mathematical relations between gradient spaces (p,q) and wavelet transform subbands are investigated. A set of formulas are provided to calculate the surface gradients from the wavelets. The DEM wavelet transform pyramid provides coarse to fine terrain structures from which the aligned regional main direction (RMD) and the local detail direction (LDD) of the terrain are automatically obtained. Based on the aligned direction of the terrain, the so-called regional main light sources (RMLs) and the local additional light sources (LALs) are automatically determined. The RML gives the regional main illumination corresponding to the RMD to provide a global shading situation, while the LAL gives the local additional illumination corresponding to the LDD to provide a detail shaded relief. The final shaded image is then obtained by a linear combination of the two shaded images with respect to the RMLs and LALs. Experimental results of the shaded images from Mars DEMs show that the proposed algorithm provides optimally shaded relief images.

Citation Download Citation

Xiuguang Zhou and Egon Dorrer "Adaptive algorithm of shaded-relief images from DEMs based on wavelet transform", Proc. SPIE 2646, Digital Photogrammetry and Remote Sensing '95, (1 December 1995); https://doi.org/10.1117/12.227869

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available